This protocol seeks to: 1) isolate the changes in the physiology of GnRH secretion which occur as a function of age from those due to the menopausal decline in ovarian hormonal status; 2) examine the quantitative changes in the control of pituitary gonadotropin and follistatin secretion by GnRH as a function of aging and/or ovarian hormonal status; and 3) examine the qualitative changes in pituitary gonadotropins which occur as a function of age, ovarian hormonal status and amount and frequency of GnRH.